Intrapatient variability of 18F-FDG uptake in normal tissues.

Objectives: To investigate the effect of serum glucose level and other confounding factors on the variability of maximum standardized uptake value (SUVmax) in normal tissues within the same patient on two separate occasions and to suggest an ideal reference tissue.

Materials And Methods: We retrospectively reviewed 334 18F-FDG PET/CT scans of 167 cancer patients including 38 diabetics. All patients had two studies, on average 152 ± 68 days apart.

Correlation between semiquantitative and volumetric 18F-FDG PET/computed tomography parameters and Ki-67 expression in breast cancer.

Objectives: To evaluate the relationship between semiquantitative and volumetric parameters on 18F-FDG PET/computed tomography (CT), including maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), tumor to liver ratio (TLR) and tumor to mediastinum ratio (TMR) with the level of Ki-67 expression in breast cancer.

Patient And Methods: We retrospectively reviewed 105 female patients with newly diagnosed breast cancer who underwent baseline 18F-FDG PET/CT and had immunohistochemical staining to determine the level of Ki-67 expression. The following PET parameters were measured (SUVmax, SUVmean, MTV, TLG, TLR and TMR) and correlated with level of Ki-67 expression.